The shape of the image created by a phased array transducer most closely corresponds to which shape?

• A. Square
• B. Curved
• C. Trapezoid
• D. Cone

Answer: (D)

Phased array transducers steer and focus the beam electronically, sending sound beams at many angles from a small aperture. The beams fan out as depth increases, creating a wedge-shaped region of insonation. In 2D, this angular fan appears on the screen as a sector that resembles a cone of sound emanating from the transducer. The other shapes don’t reflect this angular, diverging beam geometry: a square would imply a fixed rectangular footprint, a curved shape comes from the physical arrangement of a curved array rather than the imaging sector, and a trapezoid would suggest a different, non-angled boundary. So the image shape best corresponds to a cone.